Patent ID: 7172994

Claim:
A compound of formula selected from the group consisting of wherein R is a hydrogen or selected from the group consisting of CH 3 , C 2 H 5 , C 4 H 9 C 5 H 11 ; CH(CH 3 )CH 2 CH 2 CH 3 ; CH 2 CH(CH 3 )CH 2 CH 3 and CH 2 CH 2 CH(CH 3 )CH 3 ; cyclobutyl, cyclopentyl; CHâ•CHCH 2 CH 2 CH 3 ; CH 2 CHâ•CHCH 2 CH 3 ; CH 2 CH 2 CHâ•CHCH 3 ; and CHâ•C(CH 3 )CH 2 CH 3 .