Stereoselective reactions of acyclic allylic phosphates with organocopper reagents.
J Org Chem
; 66(16): 5552-5, 2001 Aug 10.
Article
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| MEDLINE
| ID: mdl-11485482
ABSTRACT
A series of acyclic allylic alcohols of general structure R(1)CH==CHCH(OH)R(2) were resolved by Sharpless kinetic resolution. The hydroxyl groups of these enantiomerically enriched alcohols were derivatized to diethyl phosphates, and the derivatives were reacted with organocopper reagents. Cleanest substitution reactions were observed with reagents R(3)(2)CuCNLi(2). With R(1) = Me and R(3) = n-Bu, the size of R(2) affected both the regioselectivity and stereoselectivity of the displacement. Larger R(2) groups gave higher regio- and stereoselectivities with R(2) = 3-pentyl, >98% S(N)2' regioselectivity and >98% anti stereoselectivity were observed. Bn(2)CuCNLi(2) gave stereoselectivities comparable to those observed with n-Bu(2)CuCNLi(2) but t-Bu(2)CuCNLi(2) exhibited much lower diastereofacial preference.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Org Chem
Año:
2001
Tipo del documento:
Article