# Oxidation of diols to dialdehydes

How could 1,4-butanediol be converted to 1,4-butandial (succinic aldehyde)? I thought of simple oxidation with $$\ce{CuO}$$ but apparently it yields gamma-butyrolactone according to erowid and this paper$$\ce{^{[1]}}$$. Could increasing the pH result in the formation of 1,4-butandial?

$$\ce{[1]}$$: Romaric Gérardy, Romain Morodo, Julien Estager, Patricia Luis, Damien P. Debecker, Jean-Christophe M. Monbaliu, Sustaining the Transition from a Petrobased to a Biobased Chemical Industry with Flow Chemistry, Topics in Current Chemistry, 10.1007/s41061-018-0222-3, 377, 1, (2018). (DOI)

• Alternatively, I am quite sure that PCC would stop at the aldehyde stage. Here, a complex diol with a 4-carbon chain is oxidized to dialdehyde with the "similar" PDC sciencedirect.com/science/article/abs/pii/… May 26 '19 at 9:51
• DMSO-based oxidation is another valid and widely cited in literature approach (eg. Swern Oxidation) May 26 '19 at 9:57
• Difficult stuff to handle as it is prone to polymerisation. Best stored as 2,5-dimethoxytetrahydrofuran which is functionally equivalent for synthetic purposes. May 26 '19 at 10:10
• True; speaking of that, wouldn't it be easier to convert easily accesssible tetrahydrofuran into 2,5-dimethoxytetrahydrofuran directly? How could I substitute a methoxy group into 2nd and 5th position? May 26 '19 at 10:41
• THF can be chlorinated at low temps with UV light below -10C to 2,5-dichloro-THF (ref here chempap.org/file_access.php?file=311a109.pdf) and then reacted with MeONa/MeOH to give 2,5-dimethoxy-THF. I would not call this an easy option, given that 2,5-dimethoxy-THF is widely commercially available May 26 '19 at 11:19