Table 1.

Summary of incorporation of partially assembled precursor analogues.

	Intermediate Analoguea,b	13C Enrichment	Relative RAL yieldc
0	none	none observed	1.0
1		41%	0.4
2		37%	1.0
3		15%	0.6
4		78%	1.0
5		19%	0.4
6		27%	2.0
7		8%	0.9
8		39%	2.6

	Unnatural analogued	Productione	Relative RAL yieldc
9		24%	1.3
10		25%	1.5
11		30%	2.0
12		0%	0.4

^a* indicates the location of ¹³C label;

^bready precursor structures are shown in red;

^cresorcylic acid lactone (RAL) relative yield includes DHZ, and for unnatural precursor analogs, also the amount of corresponding DHZ analogs;

^dCompounds 9–12 have incorrect stereochemistry or functionality for conversion to DHZ and are therefore (except for 12) transformed to corresponding DHZ analogs;

^eproduction is the amount of DHZ analog formed compared to the total RAL production.