Development of new synthetic methodology and asymmetric total synthesis of biologically active natural products
Currently our research group activity is primarily focused on asymmetric synthesis of biologically active natural products which included mainly the naturally occurring lactones and amino alcohols. A proline-catalysed organocatalytic route to the enantiopure synthesis of syn/anti-1,3-polyols was recently developed in our group.(Kumar et al. Org. Lett. 2009, 11, 2611).The protocol developed was further extended to the synthesis of syn/anti-1,3-amino alcohol (Kumar et al. Org. Lett. 2010,12,2762) and also syn/anti-1,3-diamines (Kumar et al. J. Org. Chem. 2013, 78,11756) which was successfully utilised for the synthesis of a variety of natural products of biological and pharmaceutical importance such as halosaline, hydroxyornithine, pseudohygroline, hyptolide and umuravumbolide etc. Based on proline catalyzed organocatalytic route, we also developed a protocol to synthesize the indolizidine, pyrrolizidine and quinolizidine ring system and further applied for the synthesis of a variety of alkaloids containing these ring systems such as lentiginosine, dihydroxypyrrolizidine, (-)-deoxoprosopinine and (+)- deoxoprosophylline etc. Besides we also synthesized several small and medium sized lactones such as Hagen`s gland lactones ( Rsc Adv. 2015, 5, 61000), (+)-petromyroxol ( Rsc Adv. 2015,5,63311), seimatopolide, (+)-monocerin, passifloricin and 14-membered macrolide Sch 725674 (Eur. J. Org. Chem. 2016,1215-26) etc. The application of above methodology for the synthesis of various natural products has been summarized in our recently published account. (See: Kumar et al. Accounts of Chemical Research 2013, 46, 289). We have also compiled the literature reports on 1, 3-polyols in the form of a review article ( Review article: Org. Biomol. Chem. 2017, 15, 733-761).