5'-chloro-5'-Deoxyadenosine (hydrate) is a nucleoside analog used as a substrate in polyketide biosynthesis. S-(5'-adenosyl)-L-methionine can be converted to 5'-chloro-5'-deoxyadenosine in a reaction catalyzed by a SAM-dependent chlorinase. Through a 7-step route, 5'-chloro-5'-deoxyadenosine can be converted to chloroethylmalonyl-CoA, which has been shown to be involved in the biosynthesis of the anticancer agent salinosporamide A in the marine bacterium S. tropica.

References:
[1]1. Eustáquio, A.S., McGlinchey, R.P., Liu, Y., et al. Biosynthesis of the salinosporamide A polyketide synthase substrate chloroethylmalonyl-coenzyme A from S-adenosyl-L-methionine Proc. Natl. Acad. Sci. USA 106(30), 12295-12300 (2009).