Efficient stereoconservative synthesis of 1-substituted (S)- and
申请人:Astra Lakemedel Aktiebolag
公开号:US05300660A1
公开(公告)日:1994-04-05
Stereoconservative method for preparation of an (R)- or (S)-isomer of the compound of the formula I with at least 95% optical purity ##STR1## wherein R.sup.1 is a hydrogen atom, a saturated or unsaturated lower alkyl group, a cycloalkyl group, or a group (CH.sub.2).sub.m Ph wherein m is 0-3 and Ph is a substituted or unsubstituted phenyl group including 1) O,N-dialkylation, directly or stepwise of (R)- or (S)-proline 2) aminolysis 3) reduction to formation of the (R)- or (S)-isomer of the compound of the formula I, and new intermediates II and III in optical active form obtained by the reaction steps above and wherein R.sup.2 is defined as R.sup.1 above. ##STR2##
An Experimental and Computational Study of Stereoselectivity and Reactivity in Lewis Acid Promoted Lithiation-Substitution of Tertiary Amines
作者:Satinder V. Kessar、Paramjit Singh、Kamal Nain Singh、P. Venugopalan、Amarjit Kaur、Prasad V. Bharatam、Arvind K. Sharma
DOI:10.1021/ja0675144
日期:2007.4.1
electrophile addition the enantioselectivity is reversed. Similarly, in the reaction of BF3-indolizidine complex syn substitution (dr 97:3) occurs but with a warm−cool cycle the syn−anti ratio gets changed to 41:59. These results indicate initial syn lithiation and formation of excess of the antiintermediate on equilibration. DFT calculations at the B3LYP/6-31+G* level show the synintermediate to be stable
Intermediates for the stereoconservative synthesis of 1-substituted
申请人:Aktiebolaget Astra
公开号:US05468876A1
公开(公告)日:1995-11-21
Disclosed are (R)- and (S)-isomers of the compounds of the Formulas II and III with at least 95% optical purity ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and represent a hydrogen atom, a lower alkyl, lower alkenyl or lower alkynyl group, a cycloalkyl group or a group (CH.sub.2).sub.m Ph, wherein m is 0-3 and Ph is a substituted or unsubstituted phenyl group. These compounds are intermediates in the stereoconservative synthesis of 1-substituted (S)- and (R)-2-aminomethylpyrrolidines.
Provided is a hair dyeing composition, containing a first part containing (a) a nitrogen-containing compound expressed by the general formula (1) or a salt thereof and a second part containing a component (b) of an oxidizing agent, wherein a pH upon use is 7.5 to 12,
wherein n=1 or 2, R
1
and R
3
to R
5
represent H, a hydroxy group, and an alkyl group with C12 or less optionally having a substituent, R
2
represents a hydroxy group, —R or —OR, in which R means the same as R
1
to R
5
, and two or more of R
1
to R
5
may be taken together to form a 3 to 8 membered-ring optionally having a substituent.
FUNCTIONALIZED NON-PHENOLIC AMINO ACIDS AND ABSORBABLE POLYMERS THEREFROM
申请人:Bezwada Biomedical, LLC
公开号:US20130116446A1
公开(公告)日:2013-05-09
The present invention relates to compound of formula I, which are functionalized, non-phenolic amino acids, and polymers formed from the same.
Polymers formed from the functionalized amino acids are expected to have controllable degradation profiles, enabling them to release an active component over a desired time range. The polymers are also expected to be useful in a variety of medical applications.