US 9,809,566 B2
Organocatalytic process for asymmetric synthesis of decanolides
Varun Rawat, Pune (IN); Soumen Dey, Pune (IN); Anil Maruti Shelke, Pune (IN); Gurunath Mallappa Suryavanshi, Pune (IN); and Arumugam Sudalai, Pune (IN)
Assigned to Council of Scientific and Industrial Research, New Delhi (IN)
Filed by Council of Scientific and Industrial Research, New Delhi (IN)
Filed on May 27, 2016, as Appl. No. 15/167,337.
Application 15/167,337 is a division of application No. 14/426,305, granted, now 9,353,077, previously published as PCT/IN2013/000542, filed on Sep. 6, 2013.
Claims priority of application No. 2765/DEL/2012 (IN), filed on Sep. 6, 2012.
Prior Publication US 2016/0272609 A1, Sep. 22, 2016
Int. Cl. C07D 313/04 (2006.01); C07D 313/00 (2006.01)
CPC C07D 313/00 (2013.01) [C07B 2200/07 (2013.01)] 1 Claim
 
1. An organo catalytic process for the preparation of decanolides of Formula Ic

OG Complex Work Unit Drawing
wherein the said process comprising the steps of:
i) allylboration of aldehyde (1)

OG Complex Work Unit Drawing
 in presence of allyldiisopinocamphenylborane at temperature in the range of −120° C. to −80° C. for 1-2 hours in non-polar organic solvents selected from the group consisting of diethyl ether, pentane, cyclopentane, benzene, toluene, 1,4-dioxane, chloroform, and mixtures thereof followed by treatment with NaOH and aqueous H2O2 to obtain chiral allylic alcohol (3)

OG Complex Work Unit Drawing
ii) esterification of allylic alcohol (3) with butyldimethylsilyl(TBS) protected carboxylic acid (15)

OG Complex Work Unit Drawing
 in presence of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, 4-dimethylaminopyridine in DCM at temperature range 0° to 30° C. for 5 to 8 hours with subsequent deprotection of TBS in presence of tetra-n-butylammonium fluoride in THF for 6-8 hours yields allylic alcohol (17)

OG Complex Work Unit Drawing
and
iii) ring closing metathesis reaction of compound (17) in presence of Grubbs II catalyst (5 to 15%) in dry CH2Cl2 for 18-24 hours to obtain decanolides of Formula Ic.