Highly Diastereoselective Synthesis of <i>vicinal</i> Quaternary and Tertiary Stereocenters Using the Iodo-aldol Cyclization
作者:Frederic Douelle、Amy S. Capes、Michael F. Greaney
DOI:10.1021/ol070482k
日期:2007.5.1
The intramolecular iodo-aldol cyclization of alpha-substituted enoate aldehydes and ketones is described. Using prochiral starting materials, the reaction produces hetero- and carbocycles containing quaternary centers adjacent to secondary or tertiary centers. The reactions occur in good yields and are highly selective for the trans-products, having the hydroxyl and iodomethyl groups on opposite faces of the ring system.
BLOCK COPOLYMERS
申请人:Takahashi Eiji
公开号:US20090253867A1
公开(公告)日:2009-10-08
It is to provide a block copolymer that can form a microphase separation structure even with a small molecular size, and that can form a microphase separation structure with a small domain size.
It is a block copolymer represented by the formula A-C-B (wherein A represents a segment which is a homopolymer or random or block copolymer consisting of at least 1 kind or repeat units represented by formula (II);
B represents a segment which is a homopolymer, or random or block copolymer consisting of at least 1 kind of repeat units represented by formula (III);
C represents A, B or A-B; however, at least 1 segment of each
A has a water-repellent group, or at least 1 segment of each B has a polar group); which block copolymer has a mass average molecular weight of
50,000
or less, and that can form a microphase separation structure.