shit like this amazes me

I didn't look to see if there was an easier way to do this or not, but it would surprise me if there weren't. Look at the transformation from 5 (the first compound) to 13, near the end.

Org. Let. ASAP

They turned a compound with a 3-carbon chain with 2 oxygenated centers into a compound with 5 skeletal carbons and 4 oxygenated centers in 13 steps. 13 steps!! They even used a chiral auxiliary to re-set the only chiral center in the starting material, making the choice of using it questionable.

The longest linear sequence is 24 steps, not including the 12 step synthesis of the other half of the target. In the end making it the crude equivalent of 1 step per member of the macrolactam, ouch.