In [stmt.do], it is stated that "the expression is contextually converted ...".

No grammar rule is provided in this paragraph, so it is a complete mystery to the reader what expression is being referred to. The expression is also called "condition" in [stmt.while], but this is not done in [stmt.do].

Also, unlike [stmt.while], the construction of the semantics does not happen in terms of goto, but is done in prose. This is another ugly asymmetry.

Last but no least, a note could be used to clarify the difference to while, or an example could show that a do ... while (false) statement is executed exactly once.