https://www.thevespiary.org/rhodium/Rhodium/hyperlab/syntheses/other_bio_ephedrine.htm (https://www.thevespiary.org/rhodium/Rhodium/hyperlab/syntheses/other_bio_ephedrine.htm)
, other aldehydes can be used in biosynthesis. But I don't read Russian and thus rely on imperfect machine translation. It seems like it could be interesting to experiment with vanillin first so as to develop technique with inexpensive, unsuspicious materials.Patent US3338796 (http://l2.espacenet.com/dips/viewer?PN=US3338796&CY=gb&LG=en&DB=EPD)