skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: A three-step enantioselective synthesis of (+)- and (−)-α-thujone
The stereocontrolled three-step synthesis of either enantiomer of α-thujone from commercially available 3-methyl-1-butyne is described. The enantioselectivity originates from a Brown crotylation which is then conferred to the all-carbon quaternary center via chirality transfer in a gold-catalyzed cycloisomerization. The route is highly atom economical and requires no protecting groups or redox manipulations.  more » « less
Award ID(s):
1919785
PAR ID:
10381872
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Organic & Biomolecular Chemistry
Volume:
19
Issue:
37
ISSN:
1477-0520
Page Range / eLocation ID:
8018 to 8020
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Purdue University Research Repository)
    This publication provides files for the finite element simulation of the mechanical behavior of a set of topologically interlocked material (TIM) systems. Files are to be executed with the FE code ABAQUS (TM), Simulia Inc., or need a file translator to be used by other codes if needed. Files are provided for even (i=10) and odd (i=11) numbered square assemblies of (i x i) blocks confined by a rigid frame and subjected to a transverse displacement load at the assembly center. The following files are provided: The simulations are executed as explicit dynamic simulations with a mass-scale approach to extract the quasi-static response. Building blocks are linear elastic and interact with neighbors by contact and friction. The following files are provided BR_tet_i6.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 6 x 6 blocks. This is the reference model 1. BR_tet_i8.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 8 x 8 blocks. This is the reference model 1. BR_tet_i10.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 10 x 10 blocks. This is the reference model 1. BR_tet_i12.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 12 x 12 blocks. This is the reference model 1. BR_tet_i5.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 5 x 5 blocks. This is the reference model 2. BR_tet_i7.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 7 x 7 blocks. This is the reference model 2. BR_tet_i9.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 9 x 9 blocks. This is the reference model 2. BR_tet_i11.inp: File for a TIM system constructed from regular, truncated tetrahedra shaped building blocks. An assembly of 11 x 11 blocks. This is the reference model 2. BT1_tet_i6.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 6 x 6 blocks. BT1_tet_i8.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 8 x 8 blocks. BT1_tet_i10.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 10 x 10 blocks. BT1_tet_i12.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 12 x 12 blocks. BT1_tet_i5.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 5 x 5 blocks. BT1_tet_i7.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 7 x 7 blocks. BT1_tet_i9.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 9 x 9 blocks. BT1_tet_i11.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 11 x 11 blocks. BT2_tet_i6.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 6 x 6 blocks. BT2_tet_i8.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 8 x 8 blocks. BT2_tet_i10.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 10 x 10 blocks. BT2_tet_i12.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 12 x 12 blocks. BT2_tet_i5.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 5 x 5 blocks. BT2_tet_i7.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 7 x 7 blocks. BT2_tet_i9.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 9 x 9 blocks. BT2_tet_i11.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 11 x 11 blocks. BT1_tet_i6_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 6 x 6 blocks. BT1_tet_i8_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 8 x 8 blocks. BT1_tet_i10_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 10 x 10 blocks. BT1_tet_i12_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 12 x 12 blocks. BT1_tet_i5_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 5 x 5 blocks. BT1_tet_i7_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 7 x 7 blocks. BT1_tet_i9_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 9 x 9 blocks. BT1_tet_i11_0_34.inp: File for a TIM system constructed from single-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 11 x 11 blocks. BT2_tet_i6_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 6 x 6 blocks. BT2_tet_i8_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 8 x 8 blocks. BT2_tet_i10_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 10 x 10 blocks. BT2_tet_i12_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 17 degree. An assembly of 12 x 12 blocks. BT2_tet_i5_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 5 x 5 blocks. BT2_tet_i7_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 7 x 7 blocks. BT2_tet_i9_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 9 x 9 blocks. BT2_tet_i11_0_34.inp: File for a TIM system constructed from double-skewed, truncated tetrahedra shaped building blocks. Skew angle is 12 degree. An assembly of 11 x 11 blocks. 
    more » « less
  2. (, Opuscula philolichenum)
    Arthonia ligniariella is reported for the first time from eastern North America based on a collection growing on lignum in North Carolina, U.S.A. Biatora appalachensis, an Appalachian endemic, is shown to be widespread throughout the Appalachian Mountains, primarily at high elevations. The only report of Fellhanera parvula from North America (Tennessee, U.S.A.) is considered to be F. bouteillei. Fellhanera subtilis, previously reported in North America from the Pacific Northwest, is reported for the first time from eastern North America (southern Appalachian Mountains). Gyalideopsis mexicana, previously reported in North America from the Yukon, Canada and New Mexico, U.S.A. is newly reported from eastern North America (southern Appalachian Mountains, North Carolina, U.S.A.). Lepra ouahensis, a sorediate species with lichexanthone and stictic acid, is reported from disjunct areas of the southern Appalachian Mountains and the Southeastern Coastal Plain. Its distribution is compared to the lichexanthone producing chemotypes of L. trachythallina and Varicellaria velata. Rockefellera crossophylla, a rare species considered extinct in Pennsylvania, U.S.A. is reported to be extant in that state. Psoronactis dilleniana is newly reported from North America from high elevations of the central and southern Appalachian Mountains (North Carolina and Virginia U.S.A.). Xenonectriella streimannii is newly reported for North America based on a collection found growing on Anaptychia palmulata in Georgia, U.S.A. 
    more » « less
  3. ; (, 2021 American Control Conference (ACC 2021))
    null (Ed.)
    In an ordinary differential equation represented by a set of state-space equations, the differential of the state vector is given by the values of a vector field evaluated at the values of the state vector. This paper focuses on the reconstruction of this vector field from noisy measurements of the state trajectories generated empirically from a physical process. For this estimation problem, a nonparametric least squares formulation is presented, which is then expressed as a linear quadratic tracking problem with a well known solution from the optimal control theory. This approach is demonstrated for experimental reconstruction of the magnetic force field around a permanent magnet from the motion trajectories of a magnetic particle attracted toward the magnet. 
    more » « less
  4. ; ; ; ; (, Zootaxa)
    Garra panitvongi, new species, is described from the Ataran River drainage, Salween River basin, of southeastern Myanmar and western Thailand. It is the sixth species of Garra known from the Salween River basin and is readily distinguished from all congeners by the red-orange color of the body and caudal fin, and a pointed proboscis with a blue stripe on each side from the anterior margin of the orbit to the tip of the proboscis and with the stripes forming a V-shape. Garra panitvongi is known in the aquarium trade as the Redtail Garra. Descriptive information is provided on poorly known species of Garra in the Salween River basin, and Garra nujiangensis is transferred to Ageneiogarra.  
    more » « less
  5. ; ; ; ; ; (, Journal of computational geometry)
    null (Ed.)
    In this paper, we show that the rigid-foldability of a given crease pattern using all creases is weakly NP-hard by a reduction from the partition problem, and that rigid-foldability with optional creases is NP-hard by a reduction from the 1-in-3 SAT problem. Unlike flat-foldabilty of origami or flexibility of other kinematic linkages, whose complexity originates in the complexity of the layer ordering and possible self-intersection of the material, rigid foldabilltiy from a planar state is hard even though there is no potential self-intersection. In fact, the complexity comes from the combinatorial behavior of the different possible rigid folding configurations at each vertex. The results underpin the fact that it is harder to fold from an unfolded sheet of paper than to unfold a folded state back to a plane, frequently encountered problem when realizing folding-based systems such as self-folding matters and reconfigurable robots. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email