Xing Chen

US Patent:

58861718, Mar 23, 1999

Filed:

May 28, 1997

Appl. No.:

8/864529

Inventors:

Guang-Zhong Wu - Somerville NJ
Xing Chen - Plainsboro NJ
Doris P. Schumacher - Bedminster NJ
Martin Steinman - Livingston NJ

Assignee:

Schering Corporation - Kenilworth NJ

International Classification:

C07D20508

US Classification:

540200

Abstract:

The invention relates to a process for producing a compound of the formula ##STR1## wherein R. sub. 1, R. sub. 2 and R. sub. 3 are as defined in the specification, which comprises the steps of: (a) reacting a lactone with an imine to obtain a chiral diol of the formula IV; (b) oxidizing the diol to obtain an aldehyde of formula V; (c) condensing the aldehyde with an enolether followed by dehydration to obtain a compound of formula VI; (d) hydrogenating the compound of formula VI to obtain a ketone of formula VII; and (e) chirally catalytically reducing the ketone, wherein steps (b)-(d) are shown in the following reaction scheme: ##STR2##.

US Patent:

57393214, Apr 14, 1998

Filed:

May 31, 1996

Appl. No.:

8/655785

Inventors:

Guang-Zhong Wu - Somerville NJ
Xing Chen - Plainsboro NJ
Doris P. Schumacher - Bedminster NJ
Martin Steinman - Livingston NJ

Assignee:

Schering Corporation - Kenilworth NJ

International Classification:

C07D20504

US Classification:

540200

Abstract:

The invention relates to a process for producing the compound of the formula ##STR1## which comprises reacting lactone of formula II ##STR2## with an imine of formula III': ##STR3## and converting the resulting chiral diol of formula VI: ##STR4## through several steps to obtain a compound of formula I'.