Pterins. Part 2. Stereochemistry of catalytic reduction of 6-methyl-and 6,7-dimethyl-pterin and of 2,4-diamino-6-methylpteridine

Abstract

Catalytic addition of two molecules of hydrogen to 7-deuterio-6-trideuteriomethylpterin yields a 0.8:1 mixture of cis- and trans-7-deuterio-6-trideuteriomethyl-5,6,7,8-tetrahydropterin. Similar reduction of 2,4-diamino-7-deuterio-6-(partial)trideuteriomethylpteridine gives a 1:1 mixture of cis- and trans-2,4-diamino-7-deuterio-6-(partial)trideuteriomethyl-5,6,7,8- tetrahydropteridine. Catalytic reduction of 6,7-dimethyl-and 6,7-bis(trideuteriomethyl)pterin, on the other hand, is stereospecific and forms only the cis-5,6,7,8-tetrahydro-derivatives. Reduction of 6,7-dimethylpterin with sodium in ethanol provides a 1:1 mixture of cis- and trans-6,7-dimethyl-5,6,7,8-tetrahydropterin. The stereochemistry of these products was deduced from 1H n.m.r. spectroscopy. Show more